Systems and methods for sleeve detection

ABSTRACT

A device, system, and method for detecting a covering sleeve on a container. A sleeve detection system includes a conveyor, a height profile acquisition device, and a processor in communication with the height profile acquisition device. The height profile acquisition device is configured to acquire height profiles of a tray traveling on the conveyor. The processor is configured to analyze height profiles received from the height profile acquisition device to determine a sleeve status of the tray. In some embodiments, a light gate is disposed across the conveyor and configured to detect the presence of a tray on the conveyor approaching the height profile acquisition device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 62/293,518, filed Feb. 10, 2016, entitled “SYSTEMS AND METHODS FORSLEEVE DETECTION,” which is hereby incorporated by reference in itsentirety and for all purposes.

BACKGROUND

Field

The disclosure relates to systems and methods for detecting the presenceor absence of a covering or sleeve on a container.

Description of the Related Art

A container of items in a distribution network can be covered by acovering. For processing the items in a container, the covering must beremoved. The covering removal is frequently automated.

SUMMARY

The systems and methods of this disclosure each have several innovativeaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope as expressed by the claims thatfollow, its more prominent features will now be discussed briefly.

In one aspect described herein, a tray processing apparatus comprises aconveyor for transporting a tray; at least one height profile sensordisposed proximate the conveyor, and configured to determine a heightprofile of the tray on the conveyor; and a processor in communicationwith the height profile sensor; wherein the processor is configured toreceive the height profile from the height profile sensor and analyzethe height profile to determine a status of the tray.

In some embodiments, the at least one height profile sensor comprises atleast one optical profile sensor.

In some embodiments, the at least one height profile sensor comprises atleast one ultrasonic profile sensor.

In some embodiments, the at least one height profile sensor comprises afirst height profile sensor and a second height profile sensor.

In some embodiments, the at least one height profile sensor is disposedon a frame connected to the conveyor such that the height profile sensoris located above the conveyor.

In some embodiments, the processor is configured to detect the presenceof a sleeve on the tray.

In some embodiments, the conveyor comprises a junction device incommunication with the processor, the junction device configured todirect the tray along a first path or a second path of the conveyorbased on the determined tray status.

In some embodiments, the apparatus tray processing apparatus furthercomprises a tray detector disposed on the conveyor at a point upstreamof the height profile sensor.

In some embodiments, the height profile acquisition device is configuredto acquire at least one height profile based on a notification receivedfrom the tray detector.

In some embodiments, the height profile acquisition device is configuredto acquire at least one height profile of the tray after a preset timedelay following the detection of the tray at the tray detector.

In some embodiments, the height profile acquisition device comprises atleast one optical profile sensor.

In some embodiments, the conveyor is configured to select a transportdestination of the tray based at least in part on a determined sleevestatus of the tray.

In some embodiments, the tray detector comprises a light gate.

In another aspect described herein, a method of detecting a sleevecomprises moving a tray along a conveyor; detecting the tray movingalong the conveyor; determining at least one height profile of the trayusing a height profile acquisition device; and analyzing the at leastone height profile of the tray to determine a sleeve status of the tray.

In some embodiments, the method further comprises determining atransport destination of the tray based at least in part on the sleevestatus of the tray.

In some embodiments, the method further comprises routing the tray to afirst or second destination according to the determined sleeve status ofthe tray.

In some embodiments, the step of analyzing the at least one heightprofile of the tray to determine a sleeve status of the tray comprisesreceiving a height profile of at least a portion of the tray,identifying a high point of the tray from the height profile of thetray; determining whether any point of the height profile relativelynearer a centerline of the conveyor than the high point is below a setlow threshold; determining the tray status as unsleeved based on thedetermined point below the set low threshold.

In some embodiments, the method further comprising determining a sleevestatus of the tray based on the total number of analysis data pointsrecorded for the tray and associated with an unsleeved status.

In some embodiments, terminating the analysis of height data pointsoccurs based on a preset data viewing scope limit.

In another aspect described herein a sleeve detection system comprisesmeans for detecting a tray in a transport system, means for determiningat least one height profile of the tray; means for analyzing the atleast one height profile of the tray to determine a sleeve status of thetray; means for determining a transport destination of the tray based atleast in part on the sleeve status of the tray; and means fortransporting the tray to the transport destination.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the disclosure will become morefully apparent from the following description and appended claims, takenin conjunction with the accompanying drawings.

FIG. 1 is a perspective view of an embodiment of a sleeve detectionsystem.

FIG. 2 is a perspective view of an embodiment of a light gate and heightprofile acquisition device in a sleeve detection system.

FIG. 3 is a block diagram of a sleeve detection system.

FIG. 4A shows a cross-sectional view of an exemplary sleeved tray with aproperly fit sleeve, taken along line 4-4′ of FIG. 2.

FIG. 4B shows a cross-sectional view of an exemplary partially filledtray without a sleeve, taken along line 4-4′ of FIG. 2.

FIG. 4C shows a cross-sectional view of an exemplary sleeved tray with aloose-fit sleeve, taken along line 4-4′ of FIG. 2.

FIG. 4D shows a cross-sectional view of an exemplary sleeved tray with acrushed sleeve, taken along line 4-4′ of FIG. 2.

FIG. 5A is a graphical representation of a height profile and acorresponding set of numeric height data points consistent with thesleeved tray of FIG. 4A.

FIG. 5B is a graphical representation of a height profile and acorresponding set of numeric height data points corresponding to thesleeveless tray of FIG. 4B.

FIG. 5C is a graphical representation of a height profile and acorresponding set of numeric height data points corresponding to theloose-fit sleeved tray of FIG. 4C.

FIG. 5D is a graphical representation of an example height profile and acorresponding set of numeric height data points corresponding to thetray with a crushed sleeve of FIG. 4D.

FIG. 6 is a flowchart illustrating an exemplary method for using asleeve detection system to determine the sleeve status of a tray.

FIG. 7 is a flowchart illustrating an exemplary method of analyzing oneor more height profiles of a tray to determine the sleeve status of atray.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings. In the drawings, similar symbols typicallyidentify similar components, unless context dictates otherwise. Thus, insome embodiments, part numbers may be used for similar components inmultiple figures, or part numbers may vary from figure to figure. Theillustrative embodiments described herein are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented. It will be readily understood that the aspects of the presentdisclosure and illustrated in the figures, can be arranged, substituted,combined, and designed in a wide variety of different configurations bya person of ordinary skill in the art, all of which are made part ofthis disclosure.

Reference in the specification to “one embodiment,” “an embodiment”, or“in some embodiments” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention. Moreover, the appearance ofthese or similar phrases throughout the specification does notnecessarily mean that these phrases all refer to the same embodiment,nor are separate or alternative embodiments necessarily mutuallyexclusive. Various features are described herein which may be exhibitedby some embodiments and not by others. Similarly, various requirementsare described which may be requirements for some embodiments but may notbe requirements for other embodiments.

In processing items in a distribution network, items can be transportedin containers, such as trays. These containers can be covered orprotected with a covering, such as a sleeve or other similar covering,which provides several advantages for processing and transport. A sleeveis a hollow covering for a tray which may have two open ends. A sleevecan be applied by sliding a tray into either of the two open ends, sothat the surfaces of the tray cover the bottom, top, and two sides ofthe tray. A sleeve may be secured after being applied to a tray by meansof an external strap. A sleeve protects the items within the tray frombeing damaged or lost by falling out of the tray. A sleeve also providesa flat upper surface that allows multiple trays to be stacked verticallyfor efficient storage or shipment. The containers may be strapped whenthey are transported between processing facilities to secure thecovering to the container. Tray sleeves may be made from cardboard,various plastics, or any similar material. Sleeves may be rigid orsemi-rigid to maintain their shape, or may be relatively flexible andmaintain their shape based on the presence of a tray within the sleeve.

When a container enters a processing facility, the covering, or sleeve,needs to be removed in order to process the items within the tray.Incoming trays which have sleeves and straps can be processed through anautomatic tray unsleever (ATU). In some embodiments, incoming trays canbe manually unsleeved. Trays whose items will not be processed at thefacility, or outgoing trays that are sleeved and strapped, may passthrough the facility and be processed on a tray transport system (TTS,or trayline) equipment without removing the sleeve. Trays of itemsintended for transportation to other processing facilities ordestinations may be generated at the processing facility. These trayscan also be processed on the TTS.

ATUs are not able to remove 100% of sleeves for various reasons,including damage or wear to sleeves, poor ATU functionality due to lackof maintenance, improper alignment of the tray in the ATU, and otherreasons. The failure of an ATU to remove a sleeve can result in a trayhaving a sleeve but not a strap. A sleeved, unstrapped tray can “walk”out of the sleeve during later trayline operations, effectively creatingan extra-long tray which reduces efficiency of trayline systems, cancreate malfunctions, and creates additional work that must be donemanually.

Additionally, there are normal trayline operations in which it would behelpful to sort trays based on their sleeved or unsleeved status. Forexample, sorting trays based on sleeve status is useful in determiningwhether to send a tray to an ATU, or where originating trays areprocessed on the same conveyor as destination trays. Although thepresent disclosure describes trays and sleeves, it will be understoodthat other containers and coverings can be used without departing fromthe scope of the present disclosure.

Sleeve detection systems can determine whether a sleeve is present on atray while the tray is in motion on a conveyor, belt, or other similardevice in a trayline. Preferably, a sleeve detection system will be ableto accurately detect a sleeve regardless of whether the sleeve isproperly fit or loosely fit, or if the sleeve has been crushed. Loosefitting of a sleeve can occur when a sleeve has been stretched aftermultiple uses, or when a defect occurs in the tray sleeving process. Theupper surface of a sleeve may be crushed if excessive weight is stackedon top of the tray or if a sudden impact occurs, such as an item fallingonto the tray. In some aspects, a sleeve detection system may beconfigured to provide sleeve status as a simple output, such as “nosleeve” or “has sleeve,” which can be used by a trayline control system.The sleeve detection systems disclosed herein include at least oneheight profile acquisition device to collect cross-sectional heightprofiles of trays. The acquired height profile information may beprocessed in real time or near-real time, as a tray is passing through asleeve detection system or shortly thereafter, to determine whether asleeve is present. In some embodiments, sleeve detection systems may beintegrated with existing barcode reading (scan) sections of a trayline,or may operate independently on a trayline. In some trayline systems,sleeve status determinations may be used as criteria for automaticsorting of trays via the trayline control system or similar traytransport management system.

FIG. 1 depicts an embodiment of a sleeve detection system 100 in anautomatic trayline system. The sleeve detection system 100 includes atrayline conveyor 102 disposed between raised sidewalls 106 and capableof transporting a tray 104 in a direction of motion 112. The sleevedetection system 100 includes a height profile acquisition device 109 ina transverse orientation across the conveyor, including one or moreoptical profile sensors 110 mounted above the conveyor. The sleevedetection system 100 further includes a transverse light gate 108mounted to the sidewalls 106. The conveyor 102 includes a first path 114and a second path 118, joined at a junction 116. The trayline conveyor102 may include a moving conveyor belt surface, a series of rollers, orany other type of linear conveying system. The conveyor 102 conveys,transports, or otherwise moves a tray in the direction of motion 112.The trayline conveyor 102 is disposed between the raised sidewalls 106to ensure that the tray 104 remains entirely on the conveyor 102.

In some embodiments, the first path 114 leads to a first destination,for example, to a tray unsleeving apparatus, and the second path 118leads to a second destination, for example, a tray processing apparatusfor unsleeved trays. The junction 116 can be a diverter gate, a rotatingplatform, or other similar feature that can route a tray 104 alongeither the first path 114 or the second path 116 according to a signalreceived from the optical profile sensor 110, or from a processor incommunication with the height profile acquisition device 109. Thejunction 116 can have a controller (not shown) and a motor (not shown),the controller configured to receive a signal from the height profileacquisition device 109. The controller receives the signal, which canbe, for example, “sleeve detected” or “no sleeve detected”, or the like.The controller instructs the motor to move the junction 116 to directthe tray 104 along the appropriate path: along the first path 114 if“sleeve detected,” or along the second path if“no sleeve detected.”

The light gate 108 comprises a sensing system having posts 108 a and 108b located on and extending vertically from the sidewalls 106 in aposition so as to transmit a sensing signal such as a beam 108 c whichextends perpendicular to the direction of motion 112 above and acrossthe surface of the conveyor 102. The light gate 108 is located on thesidewalls 106 at a location that is separated from the height profileacquisition device 109 in a direction that is opposite the direction ofmotion 112, so that objects traveling along the conveyor 102 will reachthe light gate 108 before reaching the height profile acquisition device109. As the tray 104 moves along the conveyor 102, it passes through andinterrupts the beam 108 c of the light gate 108. In response todetecting the tray 104 at the light gate 108, the system 100 causes theheight profile acquisition device 109 to acquire one or more heightprofiles of the tray 104, either immediately or after a predeterminedtime delay, in order to determine whether the tray 104 has a sleeve. Thelight gate 108 and height profile acquisition device 109 are discussedin greater detail below with reference to FIGS. 2 and 3.

The system 100 determines a sleeve status of the tray 104. Methods fordetermining sleeve status are described in detail below with referenceto FIGS. 5-7. Based on the sleeve status, the system 100 can divert thetray along the first path 114 or along the second path 118 at thejunction 116. The first path 114 leads to processing equipment forunsleeved trays, such as destination sorting, tray sleeving equipment,or the like. The second path 118 leads to another piece of trayprocessing equipment, such as an ATU or the like. In some embodiments,the second path 118 delivers the tray 104 to a human operator ortechnician for manual evaluation or processing. The determination tosend the tray 104 along the first path 114 or along the second path 118is made based at least in part on height profiles received from theheight profile acquisition device 109 and/or a determined sleeve statusof the tray 104.

FIG. 2 depicts an exemplary arrangement of a light gate 202 and heightprofile acquisition device 203 in an embodiment of a sleeve detectionsystem 200. The light gate 202 and the height profile acquisition device203 are mounted on a conveyor 210 with sidewalls 218. The light gate 202includes one or more light sensors 212. The height profile acquisitiondevice 203 includes a vertically oriented mounting platform 220 disposedacross the conveyor 210, perpendicular to a direction of motion 208. Atleast one optical profile sensor 204 is mounted on the mounting platform220 above the conveyor 210. The optical profile sensors emit a signal214, which can be a light signal, IR, UV, or other suitableelectromagnetic radiation. In some embodiments, non-optical profilesensing methods, such as ultrasound, may be used. In some embodiments,commercially available optical profile sensors such as the LeuzeElectronic LRS 36 may be used.

The optical profile sensors 204 may be located in any position wherethey are capable of observing, sensing, scanning, or otherwise detectinga surface of a tray 206 on the conveyor 210. In some embodiments, theoptical profile sensors 204 are located at the sides of the conveyor210. In some embodiments, the optical profile sensors 204 are locatedabove the conveyor 210. For example, the optical profile sensor 204 canbe secured to the conveyor sidewall 218, another piece of traylineequipment, or the separate frame or mounting platform 220. When mountedabove the conveyor 210, the optical profile sensor(s) 204 must belocated high enough so as to avoid physically impeding the passage ofthe tray 206 along the conveyor 210.

Any number of optical profile sensors 204 may be used in the sleevedetection system 200. In some embodiments, a single optical profilesensor 204 provides sufficient measurement capability. The singleoptical profile sensor 204 can scan a cross-section of the entire uppersurface of a tray, or it can scan a portion of the upper surface. Insome embodiments, two or more optical profile sensors 204 are used. Forexample, as many as ten or twenty optical profile sensors 204 couldpotentially be used in some embodiments, especially where a very highdegree of precision is desired, because such devices frequently operatemost precisely within smaller viewing angles. In embodiments where twooptical profile sensors 204 are used, the two optical profile sensors204 are spaced across the width of the conveyor 210, and each capturesheight profiles of approximately one half of the conveyor/tray surfacearea.

As described above with reference to FIG. 1, the arrangement isconfigured so that the tray 206 moving in the direction of motion 208 ofthe conveyor 210 passes through the light gate 202 before passing underthe height profile acquisition device 203. The sensors 212 of the lightgate 202 can include one or more position sensors, photoelectricsensors, retro reflective sensors, electro-optical sensors, proximitysensors, or the like. In some embodiments, the light gate 202 delivers astatus of “open” while no object is present in the light gate. When anobject passes through and interrupts the light gate 202, the light gate202 is triggered and delivers a status of “closed.” The light gate 202remains triggered so long as the object remains within the light gate202. In some embodiments, the light gate 202 remains closed for apredetermined period of time following triggering. In some embodiments,the light gate 202 remains closed following triggering until anothertriggering event occurs.

When the light gate 202 is closed, the light gate 202 detects thepresence of the tray 206 on the conveyor 210. The system 200 then causesthe height profile acquisition device 203 to take one or more heightprofiles of the tray 206. The optical profile sensors 204 acquireprofiles of the tray 206 based on scanning using laser light or otheroptical distance measuring technology. In some embodiments, transverseheight profiles are measured along the width of the tray 206,perpendicular to the direction of motion 208. In some embodiments,longitudinal height profiles may be measured along the length of thetray 206, along the direction of motion 208, either instead of or inaddition to transverse height profiles along the width of the tray 206.Longitudinal height profiles are captured, for example, by repeatedlymeasuring a height of the tray 206 as the tray 206 passes under thestationary optical profile sensor 204. The scanned region for atransverse height profile includes a portion of an upper surface 216 ofthe conveyor sidewalls 218 and/or a portion of the surface of theconveyor 210 so as to provide at least one reference height for lateranalysis of sleeve status. In some embodiments, the scanned regionincludes the furthest point that the sidewall of the tray 206 can extendlaterally over the conveyor sidewalls 218, so that the high point ofevery tray can be detected. Sleeve status analysis is discussed ingreater detail below with reference to FIGS. 6 and 7.

In some embodiments, the detection of the tray 206 at the light gate 202initiates a time delay before height profiles are taken. A time delayallows the conveyor 210 to move the tray 206 to a position at leastpartially below the height profile acquisition device 203. The timedelay can be predetermined, based at least in part on the speed of theconveyor 210 and the distance between the light gate 202 and the heightprofile acquisition device 203. In this manner the system 200 can avoidwasting time and processing capacity analyzing height profiles of anempty portion of the conveyor 210.

FIG. 3 depicts a block diagram of a sleeve detection system 300 inaccordance with an exemplary embodiment. The sleeve detection system 300includes a light gate 305 in communication with a height profileacquisition device 310, which includes at least one optical profilesensor 312, a processor 314, and a memory 316. The processor is incommunication with a trayline conveyor 320, an ATU 322, and anotification device 324.

The optical profile sensor operates by emitting a beam or beams 317 ofelectromagnetic radiation and detecting a reflected portion 318 of theemitted electromagnetic radiation 317. The electromagnetic radiation 317can be laser light, infrared light, ultraviolet light, visible light,radio waves, or the like. In some embodiments, non-optical detectionmethods such as ultrasonic distance sensing or sonar are used. In someembodiments, the sensor 312 has sufficient resolution to be able todetect and distinguish from its surroundings, the sidewall of a tray104, which can be in the range of 2-3 mm in thickness. The opticalprofile sensor 312 is in communication with the processor 314 includingcommands to acquire one or more height profiles. The optical profilesensor 312 can communicate acquired height profiles, error messagesrelated to height profile acquisition failure, or other information tothe processor 314. In some embodiments, the height profile acquisitiondevice 310 includes more than one optical profile sensor 312, asdescribed above with reference to FIG. 2. For example, the opticalprofile sensor 312 scanning objects below might produce less accurateresults for points at greater horizontal distances from the midpoint ofthe scan range. Using two profile sensors 312, each scanning one half ofthe width of the conveyor, can thus reduce this error to improve theaccuracy and/or efficiency of the scanning process, especially whererelatively wide conveyors are used.

The processor 314 includes circuitry configured to analyze heightprofiles to determine sleeve status of a tray 104, initiate heightprofile acquisition, and/or output a sleeve status or other commands.The processor 314 receives communications from the light gate 305, suchas the light gates 108 and 202 described above with reference to FIGS. 1and 2. In some embodiments, the light gate 305 sends a notification tothe processor 314 that a tray has been detected. In response to anotification that a tray is present, the processor 314 sends a commandto the optical profile sensor 312 to take one or more height profiles ofthe tray, either immediately or after a predetermined time delay. Thetime delay can be based on the physical distance separating the lightgate 108 and the optical profile sensor 110, on the speed of theconveyor 102, or both.

The processor 314 also receives communications from the optical profilesensor 312, including acquired height profiles or error messages relatedto height profile acquisition failure, as described above. Uponreceiving a height profile from the optical profile sensor 312, theprocessor 314 may immediately analyze the height profile to determinesleeve status, or may send the height profile data to the memory unit316 for storage and/or later analysis. In some embodiments, multipleheight profiles are used to make a sleeve status determination. Wheremultiple height profiles are used, the processor 314 can analyze two ormore profiles simultaneously received from multiple optical profilesensors 312, and/or any number of height profiles stored in the memoryunit 316.

The processor 314 sends messages to various external devices outside ofthe height profile acquisition device 310. For example, the processor314 can send a command to the conveyor 320 to cause the conveyor 320 tosend a tray to an alternate location based on its sleeved or unsleevedstatus, as described above with reference to FIG. 1. For example, acommand from the processor 314 to the conveyor 320 might cause a tray tobe sent to the ATU 322, or directed to a location for human interventionor evaluation. In some embodiments, the processor 314 can send a commandto the ATU 322 to cause the ATU 322 to unsleeve or not unsleeve a traybased on the determined sleeve status of the tray. In some embodiments,the processor 314 sends a communication to the notification device 324to notify an operator of the status of a tray or an error in the sleevestatus evaluation process. The notification device 324 can include anycombination of lights and/or sounds to attract the attention of a nearbyoperator, a message displayed on a notification screen of the sleevedetection system or of another device, a message sent to a personalcommunication device of an operator, or any other system configured toalert an operator of a tray status.

FIGS. 4A, 4B, 4C, and 4D illustrate four potential sleeve configurationsthat are at least partially exemplary of the many configurations thatmay exist with trays in a trayline. Each of FIGS. 4A, 4B, 4C, and 4Dshows a cross-sectional view of a tray 400 on a conveyor 402 bounded byconveyor sidewalls 404. The trays 400 in FIGS. 4A, 4C, and 4D arevarious types of sleeved trays, while the tray 400 in FIG. 4B does nothave a sleeve. For simplicity, any tray contents 406 are not shown forthe sleeved trays 400 of FIG. 4A, 4C, or 4D because the sleeve shieldsthe contour of the tray contents from the height profile acquisitiondevice 109. Because the tray 400 of FIG. 4B does not have a sleeve, thecontents 406 of the tray 400 will be visible to a height profileacquisition device mounted above the conveyor 402. Thus, the heightprofile acquired by the height profile acquisition device for thesleeveless tray 400 will be determined by the shape of the tray'scontents 406, while the height profile for the tray 400 with a sleevewill be determined by the shape of an upper surface 410 of a sleeve 408.

The tray 400 depicted in FIG. 4A has a properly fit sleeve 408. Aprimary characteristic of the properly-fit sleeve 408 is a substantiallyor mostly flat, level upper surface 410, running substantially parallelto the conveyor 402 and the bottom of the tray 400. In contrast, thetray 400 depicted in FIG. 4C has a loose-fitting sleeve 408, whichresults in a sagging or concave upper surface 410. In FIG. 4D, thesleeve 408 is crushed, which can occur as a result of a sudden impact orexcess weight being placed on top of the sleeve 408 during transit orstorage of the trays 400. The crushed sleeve 408 has a deeply indentedupper surface 410. The crushed upper sleeve surface 410 may be indentedor deformed far enough from the substantially flat upper surface 410shown in FIG. 4A as to cause a false “no sleeve” indication during thesleeve status analysis under some conditions, because the crushed uppersurface 410 of the sleeve 408 follows a contour similar to the innersurface of the tray 400. Methods of detecting crushed sleeves aredescribed in greater detail below with reference to FIG. 7.

A set of height data points may be obtained in a variety of ways. Anexemplary method is described here with reference to FIG. 1 and FIGS.4A-5D. First, the height profile sensed by the optical profile sensor110 is plotted on a horizontal x-axis 532 and a vertical y-axis 534. Insome embodiments, an incremental x value is then chosen, and the y-valueof the height profile is taken at each increment. For example, if theincremental x-value is 1 mm, y-values would be taken at 1 mm, 2 mm, 3mm, etc. In some embodiments, the incremental x-value can be smaller orlarger than 1 mm. These sampled y-values are recorded across the x-axis532 at each incremental x-value as a set of height data points.

In some embodiments, the height profile is divided into bins of a setwidth along the x-axis 532, and the average height within each binevaluated to determine a height data point. In some embodiments, eachbin is divided in to a number of increments, and a height for eachincrement recorded. The heights for each increment within the bin arerecorded and averaged to obtain the average height within each bin. Theincremental x-value or bin width should be small enough so as to capturean accurate representation of the vertical profile of the tray, but notso small as to exceed the resolution limit of the optical profile sensoror create an unduly large number of data points that may cause delays orerrors in processing. It is expected that a person having ordinary skillin the art will be able to determine an appropriate incremental x-valueor bin size†. It is noted that the numeric height data sets 504, 508,512, 516 depicted in FIGS. SA, 5B, SC, and SD are simplified fordemonstration purposes. In most embodiments, a height profile of a traywill be converted into a much larger set of points corresponding to asmaller incremental x-value. In some cases, appropriate incrementalx-values may result in numeric height data sets with dozens, hundreds,or even thousands of points representing a scanned height profile.

FIGS. 5A, 5B, 5C, and 5D depict example height profiles 522 andcorresponding sets of numeric height data points 504, 508, 512, 516corresponding to the trays depicted in the cross-sectional views ofFIGS. 4A, 4B, 4C, and 4D, respectively. When the optical profile sensor110 mounted above the conveyor 402 is used to capture height profiledata, the output of the optical profile sensor 110 can be represented asa linear profile of only the upper surface of the objects detected bythe optical profile sensor 110. Accordingly, the height profiles 522 inFIGS. 5A-D can comprise several discrete segments or components whichcorrespond to various features of the conveyor and trays in the sleevedetection system. The segments of the height profile include a conveyorsurface segment 518 (corresponding to the surface of the conveyor 402),a sidewall surface segment 520 (corresponding to the conveyor sidewalls404), a top surface segment 522 (which corresponds to the surface of thesleeve 408, or if there is no sleeve, with the contents of the tray400), and a tray sidewall segment 526 (corresponding to the sidewall andbottom surface of the tray 400 if no sleeve 408 is present). In somecases a tray may be oriented at an angle or shifted/justified toward theleft or right of the conveyor, resulting in a height profile that doesnot include the conveyor surface 518 on one or both sides of the tray.As described below with reference to FIG. 7, such rotation, shifting, orjustification of a tray will not prevent accurate sleeve statusdetermination when the methods described herein are applied.

The height profile depicted in FIG. 5A corresponds to the sleeved tray400 of FIG. 4A. Here, the height profile includes the generally straighthorizontal portion 522 corresponding to the generally straight uppersurface 410 of the properly-fit sleeve 408 as depicted in FIG. 4A. Theheight profile also includes the segments 518 and 520 representing thedetected height of the conveyor 402 and the sidewalls 404, respectively.

The height profile depicted in FIG. 5B corresponds with the sleevelesstray of FIG. 4B. Unlike the height profile of the sleeved tray of FIG.4A, the height profile of the sleeveless tray is of a more irregularshape, with the top surface segments 522 corresponding to the uppersurface of the contents 406 of the tray 400 as depicted in FIG. 4B. Theabsence of a sleeve may also cause the height profile to include thetray sidewall surface segments 526 corresponding to the interiorsurfaces of the sides and bottom of the tray 400. For sleeveless traysgenerally, at least a small portion of the bottom or lower internalsidewalls of the tray 400 may be visible to the optical profile sensor110 mounted above a conveyor, even when the sleeveless tray is mostlyfilled with items.

Moving to FIG. 5C, the height profile corresponds with the loosely-fitsleeve on the tray 400 of FIG. 4C. Here, the height profile includes thetop surface segment 522 which corresponds to the sagging upper surface410 of the loose-fit sleeve 408 depicted in FIG. 4C. Similarly, theheight profile depicted in FIG. 5D corresponds with the tray withcrushed sleeve of FIG. 4D. In FIG. 5D, the top surface segment 522 has amore significantly concave shape which corresponds to the deeplyindented upper surface 410 of the crushed sleeve 408 depicted in FIG.4D. As depicted in FIGS. 5C and 5D, the height of the top surfacesegment 522 is a continuous line following the contour of the sleeve408. In some embodiments, the surface segment 522 of a tray 400 of FIG.4C or 4D may be a series of points taken at the x-value increment, andmay appear as points, or short line segments. In some embodiments, thepoints taken at the x-value increment may be fit to a curve, or may beconnected in a segmented line.

Referring again to FIGS. 5A, 5B, 5C, and 5D, every height profile isconverted to a set of numeric height data points, or every set ofnumeric height data points can be converted to a height profile Forexample, the set of height data points 504, 508, 512, and 516 arederived from the height profiles depicted in FIGS. 5A-D, respectively.In some embodiments, an optical profile sensor provides an outputconsisting of only a set of height data points, rather than atwo-dimensional height profile. In such embodiments, the set of heightdata points obtained from the optical profile sensor is used directlyfor analysis without requiring the conversion steps described below.

FIG. 6 is a flowchart illustrating an exemplary method 600 for using asleeve detection system to determine the sleeve status of a tray. Themethod 600 can be performed automatically by a computer systemintegrated with a sleeve detection system in a trayline as depicted inFIG. 1.

The method 600 begins with block 602, where a tray is detected at thelight gate 108. The light gate 108 includes any of various types ofsensors as described above with reference to FIG. 2. The light gate 108is disposed across the conveyor 102 of a trayline, so as to cause thelight gate 108 to be activated any time a tray 104 reaches the lightgate 108 while traveling on the conveyor 102. After the tray 104 isdetected at the light gate 108, the method 600 continues to block 604.

At block 604, the method 600 waits for a predetermined time delay. Insome embodiments, the light gate 108 is located some distance along theconveyor 102 from the height profile acquisition device 109. Thus, atime delay improves the efficiency and accuracy of the method 600 byallowing the detected tray 104 to travel from the light gate 108 to aposition along the conveyor 102 directly below the height profileacquisition device 109 before height profiles are taken. The duration ofthe time delay may be selectable by a human operator, or may be anautomatic function. In some embodiments, the time delay is manually orautomatically selected based on the speed of the conveyor and thedistance between the light gate 108 and the height profile acquisitiondevice 109. In some embodiments, the computer system is configured toautomatically adjust the time delay based on changes in the speed of theconveyor. After the predetermined time delay elapses, the method 600continues to block 606.

At block 606, one or more height profiles of the tray 104 are taken bythe height profile acquisition device 109. In some embodiments, themethod requires only a single height profile to be taken. In otherembodiments, the method requires two or more height profiles to be takenas the tray passes by the height profile acquisition device 109. Eachheight profile will correspond to a different portion of the traybecause height profiles are taken as the tray 104 is moving by thestationary height profile acquisition device 109. Accordingly, the useof multiple height profiles increases the confidence and/or accuracy ofa sleeve status determination by reducing the effect of a singleanomalous height profile or of a small irregularity in the geometry of atray 104 in the system. In some embodiments, the height profileacquisition device 109 continues taking height profiles as long as thelight gate 108 remains triggered, or “open.” The acquisition of heightprofiles terminates when the light gate 108 no longer detects thepresence of a portion of the tray 104.

After one or more height profiles of the tray are taken, the method 600continues to block 608, where the one or more height profiles arestored. Storage occurs in the computer memory unit 316, which can be apart of the height profile acquisition device 310 or part of a separatecomputer system as described elsewhere herein. In some embodiments,storage is temporary with height profiles being stored only until theyare analyzed to determine sleeve status and automatically deletedthereafter. In some embodiments, height profiles are stored longer orindefinitely.

After one or more height profiles of the tray are stored, the method 600continues to decision state 610, where a sleeve status of the tray 104is determined based on the one or more height profiles. In someembodiments, the system can return a sleeve status of the tray 104 ofeither “sleeve” or “no sleeve,” depending on whether a sleeve isdetected on the tray 104. In some embodiments, additional sleeve statusoptions are available. For example, the sleeve detection system might beable to detect deviations from ideal conditions such as a dented sleeve,or abnormal conditions such as a tray partially within a sleeve. Methodsfor analyzing height profiles to determine the sleeve status of a trayare discussed in detail below with reference to FIG. 7. After a sleevestatus of the tray 104 is determined, the method 600 either returns a“no sleeve” status 620 if it is determined that the tray 104 does nothave a sleeve, or returns a “sleeve” status 630 if it is determined thatthe tray 104 has a sleeve. Any necessary action, such as removing thetray 104, sending the tray 104 to an ATU, or removing the tray 104 fromthe conveyor 102 for operator intervention, can be taken after thesleeve status is determined. For example, in the system depicted in FIG.1, the tray is sent along the first path 114 for appropriate processingif determined to have a “no sleeve” status, and is sent along the secondpath 118 to an ATU if determined to have a “sleeve” status. Anotification can be sent to an operator based on either or bothoutcomes. After a sleeve status is returned, the method continues toblock 640, where it awaits the next tray before returning to block 602to repeat indefinitely.

FIG. 7 is a flowchart illustrating in greater detail an exemplary method700 of analyzing one or more height profiles of a tray to determine thesleeve status of the tray. Sleeve status analysis can be performed bythe processor 314 of the height profile acquisition device 310, or byother processing circuitry connected to a sleeve detection system, suchas an external computer system. The method 700 begins at block 702 byreceiving a height profile of at least a portion of a tray including atleast one wall of the tray. The height profile is received from a heightprofile acquisition device 109 as described above with reference to FIG.1, or from any other system configured to capture height profiles. Insome embodiments, the height profile includes a set of height datapoints or a two-dimensional profile which is converted to a set ofheight data points for analysis, as described above with reference toFIG. 6.

After the height profile is received, the method 700 continues to block704, where height data points are analyzed from the outside in to find ahigh point of the tray. Outside-in analysis of a height profile beginswith data points corresponding to the conveyor sidewalls 404. The heightof the conveyor sidewall 404 is used as a high threshold value, so thatthe detection of a point higher than the conveyor sidewall 404 willindicate the initial high point of the tray 400, located at the outeredge of the tray 400. Using the conveyor sidewall height as a highthreshold is an effective way to detect the outer edge of the tray 400because trays are generally taller than the sidewalls 404 of traylineconveyors. Moreover, locating the tray edge by using a high threshold,rather than looking for a particular height or lateral location, allowsfor trays of various heights, lengths, widths, and orientations to bedetected by the same sleeve detection system.

When the high point of the tray 400 is determined, the method continuesto block 706, where the method continues analyzing height data points todetermine if any values exist below a set low threshold. The lowthreshold should be a predetermined value lower than the high point ofthe tray 400, but higher than the inside bottom surface of the tray 400.Preferably, the low threshold will be set at a height value likely to beobserved when a sleeveless tray passes through the sleeve detectionsystem, but unlikely to be observed for a sleeved tray. For example, thelow threshold can be somewhat lower than the high point to avoid a false“no sleeve” detection when a loose-fit sleeve sags lower than the highpoint. However, the low threshold should also be somewhat higher thanthe inside bottom surface of the tray because sleeveless trays sometimescontain letters, packages, or other items that completely cover theinside bottom of the tray 400. In a partially-filled sleeveless tray,the lowest height profile is likely to occur at a point along the slopedinner side wall of the tray.

After the analysis of height data points has begun, the method 700continues analyzing additional height data points until the method 700moves to block 708, where it stops analyzing height data points when itreaches either the end of the set of height data points or a presetviewing scope limit. A preset viewing scope limit is a set maximumnumber of data points to consider in a single height profile analysis,based on the distance along the horizontal cross-section of the conveyor102 and/or tray 104. A preset viewing scope limit can help to avoidmistakenly identifying sleeved trays with crushed sleeves as sleevelesstrays, as is described in greater detail below. In some embodiments, apreset viewing scope limit can be employed when multiple optical profilesensors 110 are used. For example, where two optical profile sensors 110are used, the analysis for each height profile should be terminated atthe centerline of the conveyor 102 to reduce inaccuracy resulting fromhigher viewing angles.

When the analysis of height data points has concluded, the method 700continues to decision state 710, where the method 700 determines whetherany of the analyzed height data points were lower than the preset lowthreshold. If at least one of the analyzed height data points was lowerthan the preset low threshold, the method 700 continues to block 714,where a “no sleeve” count is recorded and stored. However, if none ofthe analyzed height data points is lower than the preset low threshold,the method 700 proceeds instead to block 712. At block 712, the method700 continues without recording a “no sleeve” count, or by recording a“sleeve” or “has sleeve” count.

After block 712 or 714 is completed, the method 700 continues to block716, where blocks 700-712 or 700-714 are repeated multiple times withsome or all of the height profiles acquired as the tray 104 moves underthe height profile acquisition device 109. After some or all of theacquired height profiles have been analyzed and the corresponding “nosleeve” counts have been recorded where appropriate, the method 700continues to block 718, where the number of “no sleeve” counts iscompared with a set threshold to make the final determination of sleevestatus. For example, the method 700 might require a threshold of five“no sleeve” counts to determine that a tray does not have a sleeve. Insome embodiments, the “no sleeve” count threshold is as low as one, butcan be much larger, so long as the threshold is no greater than thetotal number of height profiles analyzed. Using a threshold greater thanone has the advantage of reducing the effect of a single erroneousreading or a physical anomaly such as a hole or puncture in the top of asleeve. If the number of “no sleeve” counts is lower than the “nosleeve” count threshold, the method 700 returns a sleeve status of “hassleeve.” If the number of“no sleeve” counts is equal to or greater thanthe “no sleeve” count threshold, the method 700 returns a sleeve statusof“no sleeve.” Once a sleeve status has been determined, the method 700continues to block 720, where the method 700 terminates. The determinedsleeve status is then used in block 610, described above with referenceto FIG. 6, so that appropriate action can be taken based on the sleevestatus of the tray 104. In some embodiments, the system can determinesleeve status by comparing the number of “no sleeve” counts with“sleeve” counts. In this alternative method, the threshold fordetermining a sleeve status can be in the form of an arithmeticdifference between the “no sleeve” and “sleeve” counts (e.g., return “nosleeve” status if there are at least 10 more “no sleeve” counts than“sleeve” counts) or in the form of a ratio (e.g., return “no sleeve”status if there are at least twice as many “no sleeve” counts as thereare “sleeve” counts).

An exemplary application of the sleeve status analysis method 700 willnow be described with simultaneous reference to FIG. 7 and the heightprofile of FIG. 5A. At block 702, a height profile is obtained from anoptical profile sensor. From the height profile, the corresponding setof height data points 504 are derived. The method 700 continues to block704, where the height data points 504 are analyzed. The first two datapoints analyzed will have a value of “6,” corresponding to the height ofthe conveyor sidewall 520. The third data point analyzed has a value of“0,” corresponding to the height of the conveyor surface 518. The fourthdata point analyzed will have a value of “10,” indicating a high pointof the tray. Having identified a high point of the tray, the method 700continues to block 706, where additional height data points are analyzedto determine if any values exist below a set low threshold. An exemplarylow threshold might be “6,” such that any points detected lower than theheight of the conveyor sidewall 520 will trigger a “no sleeve” count.The method 700 will reach the second edge of the tray, where it willagain detect the conveyor at height “0” followed by the conveyorsidewall at height “6,” proceeding to block 708 to stop analyzing heightdata. The method 700 would continue to the decision of block 710. Forthe height data set 504, corresponding to a properly-fit sleeved tray,the method 700 would not have detected any points lower than thethreshold. Thus, the method 700 would continue through block 712 toblock 716, without recording a “no sleeve” count. The method 700 wouldthen return to block 702 if additional height profiles remain to beanalyzed.

The analysis would proceed in a similar manner for the height profile ofFIG. 5B. However, because this height profile 506 corresponds to asleeveless tray, the corresponding height data set 508 is noticeablydifferent from the height data set 504. After detecting the high pointof the tray at height “10,” the method 700 would continue until reachingthe tenth point in the set, which has a value of “4.” If the same lowthreshold value of “6” is used, “4” would be lower than the lowthreshold. Thus, upon reaching block 710, the method 700 will insteaddetermine that a height below the threshold exists, and proceed to block714, where a “no sleeve” count will be recorded. The method 700 thencontinues to block 716 as described above.

In some embodiments where the analysis is terminated at the centerline,each half of the height profile 506 can be analyzed separately. Thus,after concluding the analysis of the left half of the height data set508 at block 716, the method returns to block 702 and perform the sameanalysis on the right half of the height data set 508, beginning withthe outer right edge and moving inward to the left. For the right halfof the height data set 508, the high point will again be detected atheight “10,” followed by “5” and “1.” After analyzing the remainder ofthe right half of the data set 508, the decision at block 710 will againbe answered “yes” because both “5” and “1” fall below the exemplarythreshold of 6. Again, a “no sleeve” count will be recorded at block714, and the analysis will continue to block 716 as described above.

As described above, some sleeves may be encountered with crushed uppersurfaces that can cause false “no sleeve” readings. Referring now toFIG. 5D, a height profile 514 corresponds to a crushed sleeve. A crushedsleeve can cause erroneous “no sleeve” counts to be recorded if aportion of the sleeve is crushed to a height below the low threshold.For example, if the height data set 516 is used with a low threshold of6, the point at the middle of the tray will be found below thethreshold, and a “no sleeve” count will be recorded. Selecting a lowerthreshold helps to avoid this problem. However, lowering the thresholdcan also increase the frequency of mistakenly detecting sleeveless traysas having sleeves.

In some embodiments, to avoid detecting crushed sleeves as sleevelesstrays, the preset viewing scope limit in block 708 of the method 700 canbe decreased in some embodiments. Thus, the analysis is performed basedonly on outer portions of a tray, and the middle, where low values arelikely to be found in crushed trays, is omitted. For example, whenanalyzing the height data set 516, a viewing scope limit might beselected such that only 9 points are analyzed from each side movinginward. Thus, most of the tray height profile 514 would still beanalyzed, but the middle three points of the height data set 516 wouldbe omitted from the analysis, and the false “no sleeve” count would beavoided.

Viewing scope limits are a generally effective method for avoiding themisdetection of crushed sleeves because crushed sleeves are most likelyto have their lowest points near the middle of a tray, where the sleeveis least supported. Conversely, sleeveless trays are most likely to havetheir lowest points at the edges, adjacent to the sidewalls of the tray.Thus, the points near the middle of the conveyor are least significantto the analysis, and their omission tends to reduce the frequency oferroneous sleeve status determinations.

The foregoing description details certain embodiments of the systems,devices, and methods disclosed herein. It will be appreciated, however,that no matter how detailed the foregoing appears in text, the systems,devices, and methods can be practiced in many ways. It should be notedthat the use of particular terminology when describing certain featuresor aspects of the invention should not be taken to imply that theterminology is being re-defined herein to be restricted to including anyspecific characteristics of the features or aspects of the technologywith which that terminology is associated.

It will be appreciated by those skilled in the art that variousmodifications and changes may be made without departing from the scopeof the described technology. Such modifications and changes are intendedto fall within the scope of the embodiments. It will also be appreciatedby those of skill in the art that parts included in one embodiment areinterchangeable with other embodiments; one or more parts from adepicted embodiment can be included with other depicted embodiments inany combination. For example, any of the various components describedherein and/or depicted in the Figures may be combined, interchanged orexcluded from other embodiments.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

All references cited herein are incorporated herein by reference intheir entirety. To the extent publications and patents or patentapplications incorporated by reference contradict the disclosurecontained in the specification, the specification is intended tosupersede and/or take precedence over any such contradictory material.

The term “comprising” as used herein is synonymous with “including,”“containing,” or “characterized by,” and is inclusive or open-ended anddoes not exclude additional, unrecited elements or method steps.

It is noted that some examples above may be described as a process,which is depicted as a flowchart, a flow diagram, a structure diagram,or a block diagram. Although a flowchart may describe the operations asa sequential process, many of the operations can be performed inparallel, or concurrently, and the process can be repeated. In addition,the order of the operations may be rearranged. A process is terminatedwhen its operations are completed. A process may correspond to a method,a function, a procedure, a subroutine, a subprogram, etc. When a processcorresponds to a software function, its termination corresponds to areturn of the function to the calling function or the main function.

The above description discloses several methods and materials of thepresent invention. This invention is susceptible to modifications in themethods and materials, as well as alterations in the fabrication methodsand equipment. Such modifications will become apparent to those skilledin the art from a consideration of this disclosure or practice of theinvention disclosed herein. Consequently, it is not intended that thisinvention be limited to the specific embodiments disclosed herein, butthat it cover all modifications and alternatives coming within the truescope and spirit of the invention as embodied in the attached claims.

What is claimed is:
 1. A tray processing apparatus comprising: aconveyor for transporting a tray; at least one height profile sensordisposed proximate the conveyor, and configured to determine a heightprofile of the tray on the conveyor; and a processor in communicationwith the height profile sensor, wherein the processor is configured toreceive the height profile from the height profile sensor and analyzethe height profile to determine a status of the tray.
 2. The trayprocessing apparatus of claim 1, wherein the at least one height profilesensor comprises at least one optical profile sensor.
 3. The trayprocessing apparatus of claim 1, wherein the at least one height profilesensor comprises at least one ultrasonic profile sensor.
 4. The trayprocessing apparatus of claim 1, wherein the at least one height profilesensor comprises a first height profile sensor and a second heightprofile sensor.
 5. The tray processing apparatus of claim 1, wherein theat least one height profile sensor is disposed on a frame connected tothe conveyor such that the height profile sensor is located above theconveyor.
 6. The tray processing apparatus of claim 1, wherein theprocessor is configured to detect the presence of a sleeve on the tray.7. The tray processing apparatus of claim 1, wherein the conveyorcomprises a junction device in communication with the processor, thejunction device configured to direct the tray along a first path or asecond path of the conveyor based on the determined tray status.
 8. Thetray processing apparatus of claim 1 further comprising a tray detectordisposed on the conveyor at a point upstream of the height profilesensor.
 9. The sleeve detection system of claim 1, wherein the heightprofile acquisition device is configured to acquire at least one heightprofile based on a notification received from the tray detector.
 10. Thesleeve detection system of claim 1, wherein the height profileacquisition device is configured to acquire at least one height profileof the tray after a preset time delay following the detection of thetray at the tray detector.
 11. The sleeve detection system of claim 1,wherein the height profile acquisition device comprises at least oneoptical profile sensor.
 12. The sleeve detection system of claim 1,wherein the conveyor is configured to select a transport destination ofthe tray based at least in part on a determined sleeve status of thetray.
 13. The sleeve detection system of claim 1, wherein the traydetector comprises a light gate.
 14. A method of detecting a sleevecomprising: moving a tray along a conveyor; detecting the tray movingalong the conveyor; determining at least one height profile of the trayusing a height profile acquisition device; and analyzing the at leastone height profile of the tray to determine a sleeve status of the tray.15. The sleeve detection method of claim 14, further comprisingdetermining a transport destination of the tray based at least in parton the sleeve status of the tray.
 16. The sleeve detection method ofclaim 14, further comprising routing the tray to a first or seconddestination according to the determined sleeve status of the tray. 17.The sleeve detection method of claim 14, wherein the step of analyzingthe at least one height profile of the tray to determine a sleeve statusof the tray comprises: receiving a height profile of at least a portionof the tray; identifying a high point of the tray from the heightprofile of the tray; determining whether any point of the height profilerelatively nearer a centerline of the conveyor than the identified highpoint is below a set low threshold; determining the tray status asunsleeved based on the determined point below the set low threshold. 18.The sleeve detection method of claim 17, further comprising determininga sleeve status of the tray based on the total number of analysis datapoints recorded for the tray and associated with an unsleeved status.19. The sleeve detection method of claim 17, wherein terminating theanalysis of height data points occurs based on a preset data viewingscope limit.
 20. A sleeve detection system comprising: means fordetecting a tray in a transport system; means for determining at leastone height profile of the tray; means for analyzing the at least oneheight profile of the tray to determine a sleeve status of the tray;means for determining a transport destination of the tray based at leastin part on the sleeve status of the tray; and means for transporting thetray to the transport destination.